The morphology of the articular region of the pectoral girdle and associated basals in Etmopteridae is revised in light of new evidence provided by taxa unavailable for previous studies. Such studies considered that etmopterids plesiomorphically had a single pectoral articular condyle, and only Etmopterus had two separate ones. Our reanalysis indicates that the possession of two separate condyles, one for the articulation of the propterygium and the second for the meso- and metapterygium, is the most widespread condition in this group. However, the presence of two separate articular condyles is not recovered as a synapomorphy for Etmopteridae. Previous studies also proposed that etmopterids lack a hook-like process on the anteroproximal margin of the anteriormost pectoral basal. We document that the hook-like process is plesiomorphically present in Etmopteridae, thus corroborating the hypothesis of closer relationships between this family and the other squaliforms that also share this process, namely Centrophoridae, Dalatiidae, Oxynotidae, and Somniosidae. This article is protected by copyright. All rights reserved.

中文翻译：

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灯笼鲨（Elasmobranchii：Squaliformes：Etmopteridae）胸骨的重新评估

根据以前研究无法获得的分类群提供的新证据，修改了 Etmopteridae 中胸带关节区和相关基部的形态。此类研究认为，etmopterids 有一个单一的胸骨关节髁，只有 Etmopterus 有两个独立的。我们的再分析表明，拥有两个独立的髁突，一个用于连接翼状胬肉，第二个用于中膜和后胬肉，是该组中最普遍的情况。然而，两个单独的关节髁的存在没有恢复为 Etmopteridae 的突触。以前的研究还提出，etmopterids 在最前胸基底部的前近端边缘缺乏钩状突起。我们记录了钩状过程在 Etmopteridae 中是 plesiomorphically 存在的，从而证实了这个家庭与其他也共享这个过程的角形纲之间更密切关系的假设，即 Centrophoridae、Dalatiidae、Oxynotidae 和 Somniosidae。本文受版权保护。版权所有。